Skis have been available for centuries for use on humans, sleighs, and various other snow vehicles including snowmobiles. Only until the last 50 years or so have these skis incorporated or included what have been referred to as wear or steering keel bars, runners, skags, and the like as depicted, for example, in U.S. Pat. No. 3,732,939 of Samson. The Samson runner blade is affixed to the bottom surface of a ski by three threaded studs with the front and rear ends of the bar bent so as to tuck into the bottom of the ski. This method of attachment is even popular today.
A wear, steering keel, or runner bar can perform several functions. As one name implies, a wear bar is used to lengthen the life of the under or bottom surface of the ski by focusing the contact or wear on the bar when in contact with the ground or hard surfaces. As a steering keel bar, the bar extends downwards, as in a watercraft, to stabilize and improve the steering responsiveness and capability of the ski.
The Samson patent also discloses the use of carbide chips or inserts that are affixed to the bottom of the bar to improve cornering or turning on ice or compacted snow. This is similar to ice skates having a cutting edge blade. In addition, the chips or inserts improve the wear characteristics of the bar as well as the ski.
The wear bar disclosed in the Samson patent, as well as many produced by manufacturers today, exhibits a circular cross-sectional shape with a notched longitudinal recess for affixing a chip or insert therein. The insert can be square or triangular bar stock for positioning in the wear bar recess. Wear bars also utilize inserts that have triangular or wedge-shaped configurations to further accentuate the pointed bottom edge of the bar presented to the ground, ice, or snow surface.
The problem with these round or wedge shaped wear bars is that the side of the bar directs snow or other material around or, more particularly, in a downward direction to escape causing the steering keel bar and ski to lose adhesion in a hard cornering situation. In extreme cases, dangerous loss of control can occur as the snow or other material causes the bar and ski to actually lift.